Last night was his opening night as the host with the most, and he kicked it off by collecting on some bets. And OF COURSE those bets are only with some of the most famous people in Hollywood!

Not only did Tina Fey, Seth Rogen, and Mariah Carey pop in to pay up, but Kim Kardashian and Lindsay Lohan were also on hand to fork over their cha-ching! Even Joan Rivers was there despite her almost-30-year ban that started when Johnny Carson exiled her from the show for leaving her gig as a permanent guest to go host a competing program. Along with that, her appearance on Jimmy's new show came 49 years to the day after her first appearance on Johnny's Tonight Show.

Talk about powerful! Jimmy is starting off by making things right!

But we bet you're wondering why all these celebs were handing over their hard-earned dollars??

Guess you've gotta ch-ch-check it out (above) to see what went down and which other BIG names showed up!

And while the world is collectively shaking their heads at Justin Bieber today following his DUI arrest in Florida, keep in mind that the Biebs isn't the only one who's been busted behind the wheel and over the limit!

Who else has been charged with driving while under the influence?

CLICK HERE to view the gallery, "Celebs Who Have Been Arrested On DUIs!"

CLICK HERE to view the gallery, "Celebs Who Have Been Arrested On DUIs!"

CLICK HERE to view the gallery, "Celebs Who Have Been Arrested On DUIs!"

CLICK HERE to view the gallery, "Celebs Who Have Been Arrested On DUIs!"

CLICK HERE to view the gallery, "Celebs Who Have Been Arrested On DUIs!"

A new Bill Cosby accuser's story of how he allegedly sexually assaulted her after drugging her drink is horrifying.

According to Patricia, -- who decided to keep her last name anonymous -- Bill invited her to a dinner party in 1978 after they met at a conference... a dinner party that ended up just being the two of them: